Check first the spam/bulk mail folder and avoid using the same address as "from" and "destination" for the emails.

The plugin uses the settings specified into the WordPress website to deliver the emails, if your hosting or email service has some specific restrictions like a fixed "from" address or related to the destination address you have to setup those addresses according to that restrictions.

Hi,
thx for your help.
It's seemed that's not possible to send a E-Mail to the same domain.
If I send the admin mail to a other domain that it's running ...
It's not that what I need, but I will get the Message